While top Senate Republicans have denounced Roy Moore in light of recent allegations, former Trump chief strategist Steve Bannon remains steadfast in his support for the insurgent candidate. Since leaving the White House and returning to Breitbart News, Bannon has worked to antagonize establishment Republicans and change the party. John Yang reports.

Read the Full Transcript

This evening, the NewsHour is confirming word that the Republican National Committee is severing all ties with the Moore campaign.

This exposes a growing divide between the so-called GOP establishment and a key player in President Trump's success, Steve Bannon.

John Yang has the story.

Roy Moore:

I have not been guilty of sexual misconduct with anyone.

John Yang:

That might be the defense for Roy Moore, the Republican running in Alabama's special Senate election, but while top establishment Republicans distance themselves from the candidate…

Man:

I think it would be best if Roy would just step aside.

Man:

I don't believe there'd be any place for him in the U.S. Senate.

Sen. Mitch McConnell:

I think he should step aside.

John Yang:

… the insurgent outsider who's his champion is doubling down on his support.

Steve Bannon:

Until I see additional evidence on Judge Moore, I'm standing with him.

John Yang:

Steve Bannon, the ousted White House adviser who's looking to send shockwaves through the Republican Party in 2018 and beyond.

Bannon is a divisive figure, a political lightning rod as Mr. Trump's campaign CEO, then a top White House adviser, whose seemingly outsized influence on the president made him a household name.

Alec Baldwin:

Send in Steve Bannon.

(LAUGHTER)

(CHEERING AND APPLAUSE)

Actor:

Hello, Donald. I have arrived.

John Yang:

Bannon left the White House in August amid Oval Office tensions and reports he was responsible for the president's tepid response in denouncing deadly racial violence in Charlottesville, Virginia.

President Donald Trump:

I think there is blame on both sides, and I have no doubt about it, and you don't have any doubt about it either.

John Yang:

Bannon returned to his old job as executive chairman of Breitbart News, a conservative Web site he once dubbed a platform for the alt-right.

Now he is chief antagonist for Mr. Trump and his brand of ideology, taking aim at the heart of the Senate GOP and party establishment. Bannon has threatened to identify and support primary challengers against almost every Republican running for reelection next year, except Texas Senator Ted Cruz, and some Democrats. His goal? To load the Senate with insurgents who are loyal to Mr. Trump's populist ideas and want to buck Majority Leader Mitch McConnell.

Steve Bannon:

There is a time and season for everything. And right now, it is a season of war against the GOP establishment.

Michael Steel:

It's an incredibly stupid and a counterproductive idea.

John Yang:

Michael Steel is a longtime Republican consultant, and a former aide to House Speaker John Boehner and to Jeb Bush's presidential campaign.

Michael Steel:

This isn't a matter of ideology. This is a matter of math. If you have a 52-seat majority in the Senate, where most things in order to move forward requires 60 votes, you need more Republicans, not more pure Republicans.

John Yang:

Just a year from the 2018 midterms, and Bannon has already claimed credit for upending at least three incumbents, in September, when Moore won the primary against incumbent Senator Luther Strange.

Steve Bannon:

Every person in this country should get down every night and thank God Donald Trump is president of the United States.

John Yang:

That same day, Bannon cheered when a moderate Republican from Tennessee announced he wouldn't run.

Steve Bannon:

Senator Corker stepped down today. He's not going to run for reelection.

(CHEERING AND APPLAUSE)

John Yang:

Then a new height.

Sen. Jeff Flake:

I am announcing today that my service in the Senate will conclude at the end of my term.

In Arizona, Bannon has endorsed Kelli Ward, a former state legislator.

Kelli Ward:

I think of myself as an Americanist, and I think that's what resonates so much with the people in Arizona, and I think that's what resonated with President Trump across the country. That's why he's in the White House, and that's why I will be in the Senate.

John Yang:

Ward unsuccessfully ran against Senator John McCain last year. Now she's casting herself as an American-first conservative insurgent.

Kelli Ward:

We want a secure border. We want to stop illegal immigration. We want Obamacare out of here. We want the tax code fixed. We want the military to be strong. We want all of those things, and the people who are in Washington, D.C., right now are not delivering.

John Yang:

At her kickoff party in Scottsdale, Arizona, Bannon made clear it's him and candidates like Ward vs. the establishment.

Steve Bannon:

It's an open revolt, and it should be. These people hold you in total contempt. When they attack a Donald Trump and a Dr. Kelli Ward, it's not Donald Trump and Kelli Ward they're trying to shut up. It's you they're trying to shut up.

John Yang:

His message resonated with the crowd.

Woman:

I am very unhappy with McConnell. I am very unhappy with the Senate.

Man:

I think they go back to Washington, and they just think they're set for life there. And they don't care what the hell the people think about them.

Man:

Steve Bannon is carrying on with that clear agenda that was promised to us during the Donald Trump campaign.

John Yang:

For his part, McConnell is already firing back. His super PAC, the Senate Leadership Fund, launched ads linking Ward to a conspiracy theory that the government uses airplanes to spread mind control chemicals.

Narrator:

Chemtrail Kelly's got her head in the clouds with crazy ideas.

John Yang:

He wouldn't be the first to try and clean House within his own party, says presidential historian Michael Beschloss.

Michael Beschloss:

Franklin Roosevelt tried that in 1938 with some senators, especially from the South, who were blocking his programs. And he actually would go into the home state of the senator and give speeches against him. It didn't work. He didn't get one of them elected.

If you're trying to change the party, that always happens in history over the course of a number of elections. It just doesn't happen overnight with one election night. And so, when you hear a David Plouffe or a Karl Rove say, I'm not just trying to change the party for this moment, I'm trying to change it for the next generation, that's very much within the tradition of American history.

John Yang:

Bannon also says he's looking for a long-term change. And his first test will be in 2018.